For purposes of the foregoing specification and appended claims the term “vapor,” whether or not accompanied by any words such as “moisture,” “water” or other words describing similar matter or states of matter, refers to all forms of liquid and gases not limited to water, water vapor, moisture as created by any means.
This invention addresses the condition that walls hold vapor and moisture and their inability to allow vapor and moisture to escape so the wall can dry is a major factor in the premature deterioration of a structure. Building science, construction practices and emerging energy codes have changed greatly over recent decades resulting in significantly better insulated walls. Consequently these newer wall designs allow less means for vapor and moisture to escape and less air flow. This has led to increasingly premature deterioration of walls of buildings and structures.
Established wall designs and construction are intended to keep water out of walls but not necessarily to allow them to breathe. Building wraps traditionally prevent water intrusion but do not let moisture out. A better wall design must allow for moisture and vapor to move through a predetermined path depending upon when the inside and outside temperatures have the sufficient temperature difference to create and hold excess moisture.
Further, air pressure differential from inside and outside the wall due to temperature and or wind can force moisture into the wall through the wall's surface, in addition to preventing vapor and moisture from escaping. This prevents condensation from escaping and inhibits drying. Further, when cold air contacts hot air, or vice versa, condensation occurs and moisture is formed inside the walls of buildings and structures.
As a result, moisture and water accumulates without a means to escape causing the sheathing of walls to absorb moisture. Plywood, cement board, or OSB (Oriented Strand Board), which is more prone to absorb moisture, can begin to mold, deteriorate, rot and hold more water. As the sheathing fails the weight of the finish material will begin to crack. This allows more moisture accumulation in the walls. Ultimately the finish material can fall away from the building or structure. Areas receiving 20-inches or more of rain a year are the most susceptible to this type of deterioration.
Current building science, and construction materials and practices do not provide a clear and effective means for vapor to escape from different conditions within the walls of a building or structure. “J” bead and casing beads have been used at the base of walls as a possible means for vapor to escape. A misconception is that punched drainage holes in the ground allow moisture to escape. During installation of a stucco finish these holes become blocked and the only escape for vapor is through the stucco membrane or other cladding material which promotes accelerated deterioration. This method only works in areas where no or negligible rainfall is present.
Weep screeds have been used with stucco cladding and currently are the only the vapor escape method approved by building codes and standards. Again, the weep screed is ineffective because the path for vapor to escape a weep screed is the minute space created between the finish and the upper surface of the screed as the finish cures and shrinks.
Another problem area occurs at through wall penetrations such as above windows and doors. Casing beads with drip holes as disclosed above do not provide a reliable vehicle for vapor or water escape. Further, casing beads plus a drip edges create additional problems in their attempt at solving the vapor and water intrusion/vapor escape problems. The cutting trimming of drip edges to block the assembly from water intrusion is as much a problem as providing an escape for vapor.
U.S. Pat. No. 8,584,416 is a movement control screed which provides for the movement of adjacent upper and lower masonry coatings, allowing for some drainage of water only from the upper stucco panel. The patent teaches that the device is intended to keep water out by providing for movement at the floor plates. It does not teach or claim to allow the escape of vapor or for the wall to dry. There is no provision for incorporating a defined drainage plane, that is rainscreen. Further, this device was intended for wood framed and sheathed construction with a stucco finish above and stucco over masonry or block below. The patent does not cover a three coat stucco finish above and below or stucco above and stone below.
U.S. Pat. No. 7,673,421 is a device to allow for water drainage only at floor joints. The patent teaches that the device is intended to keep water out by providing for movement at the floor plates and not to allow for vapor to escape or for the wall to dry. There is no provision for incorporating a defined drainage plane, that is a rainscreen. Further, this device was intended for wood framed and sheathed construction with a stucco finish above and stucco over masonry or block below. The patent does not cover a three coat stucco finish above and below or stucco above and stone below.
U.S. Pat. No. 7,634,883 is a device intended to move exterior water in the form of rain or condensation and drip away from the structure. The patent does not teach or claim the escape of vapor from inside the wall or for the wall to dry, nor is there any allowance for incorporating a defined drainage plane, that is a rainscreen. Further, this device is limited to wood framed and sheathed construction with a stucco finish above and stucco over masonry or block below. The patent does not cover a three coat stucco finish above and below or stucco above and stone below.
Designs currently available only use casing beads, “J’ beads, weep screeds and screeds for the mid wall juncture of finish at a floor line or dissimilar materials of a structure or a building. The current art does not facilitate the ventilation of a primary drainage cavity or the drying of the inside of the wall. Some of these areas of concern are at the base of full height walls and step walls, changes in roofline where a vertical element terminates into a non-vertical structure such as a dormer and roof for the removal of vapor from the wall. In areas as noted above where greater rainfall is typical a more defined escape means for vapor and moisture is required over current methods.
Current commercially available accessories for stucco, stone and other finishes do not address these conditions and constraints on air and vapor flow throughout a wall. Therefore a new wall design and trim accessories are necessary to accommodate the different forms and function of the building envelope and prevent premature deterioration of the walls.